4:30 p.m. is usually when my household switches from solar production to stored energy. I installed a 10kWh lithium iron phosphate battery last spring, and the change has been most noticeable on hot summer evenings. Before it, our air conditioner and induction cooker pulled electricity from the grid during the utility’s expensive peak window. Now my solar panels charge the battery through the afternoon, and the inverter carries us until bedtime.

At first, I watched the monitoring app obsessively. On a typical sunny day, it shows roughly 7kWh discharged after 4 p.m., which sounds small but adds up. My evening grid usage fell from around 9kWh to 2kWh. At my rate, that saves about $1.50 to $2.00 per day, or close to $45 in a busy summer month. The battery has not eliminated my electric bill, because we still buy power on cloudy days and pay fixed charges, but it has noticeably reduced the expensive part of the bill.

My only real hiccup happened during a week of smoke and rain. The battery reached its reserve limit earlier than expected, and the system switched to grid power before dinner. I initially thought the solar battery had failed. After checking the app, I found that I had accidentally raised the backup reserve from 20% to 60% while experimenting with settings. Dropping it back to 25% solved the issue immediately. I now leave that reserve alone unless severe weather is coming.

I also use a small 14v lithium battery for a camping refrigerator and emergency lights, separate from the main home storage system. It is not powerful enough to run household appliances, but it is convenient and easy to recharge from a compact solar panel.

The biggest practical benefit is simply using my own solar electricity after sunset. I no longer feel quite as frustrated watching daytime production go back to the grid while paying peak rates a few hours later.